GIS-based emission inventory of heavy metals from road transport and NMVOCs associated with biomass burning for megacity Delhi

Clean air is an essential requirement for human health and well-being. The rapid evolution in urbanization poses a risk to human health. The significance of robust emission inventory has intensified with scientific advancement in air quality improvement. A comprehensive GIS-based emission inventory of heavy metals and NMVOCs from road transportation, road dust, and biomass burning covering the megacity of Delhi has been prepared in this study for the base year 2018. The emission of heavy metals from biomass burning and road dust was estimated by computing the chemical constituents of PM2.5. The emission of heavy metals from all sources is estimated as 695.202 Mg/year, with Zinc (Zn similar to 48%) having the highest emissions, followed by Copper (Cu similar to 21%). The share of road transportation emissions was 78%, followed by resuspended road dust emissions at 4%. The emissions of 23 NMVOCs (1.158 Gg/year) were calculated from biomass burning (fuelwood, agricultural residue, dung cake, and coal) with Dung cake (similar to 58%) and fuelwood (similar to 41%) as the major contributors. The maximum emission was ethene (similar to 29%), and the minimum was isopropyl benzene (similar to 0.06%). The finding of this study will assist environmental policymakers and stakeholders in developing mitigation methods to reduce emissions and enhance air quality.

Automated summary

Clean air is crucial for human health and well-being, but rapid urbanization poses risks to air quality. This study presents a comprehensive GIS-based emission inventory of heavy metals and NMVOCs in Delhi, covering road transportation, road dust, and biomass burning. The findings show that heavy metal emissions are mainly from biomass burning and road dust, with Zinc being the highest contributor. Road transportation contributes the most to overall emissions, while biomass burning is a significant source of NMVOC emissions. This study provides valuable information for policymakers and stakeholders to develop effective strategies to reduce emissions and improve air quality.